UPDATE: 'Flesh-eating' bacteria kills 1 in Sarasota County

Wednesday

Jul 30, 2014 at 9:54 AMJul 30, 2014 at 1:07 PM

The health department issues a warning against eating raw oysters and exposing open flesh wounds to coastal and inland waters.

STAFF REPORT

Two Sarasota County cases this month of a serious marine bacterial infection — one of them fatal — prompted local health officials this week to issue a warning against eating raw oysters and exposing open flesh wounds to coastal and inland waters.

This urgent advisory applies pointedly to residents and visitors with chronic diseases that make them more vulnerable to the dangerous infection. Highest on the list is liver disease — including Hepatitis C and cirrhosis — but other conditions are hemochromatosis (iron overload), diabetes, cancer, stomach disorders or any illness or treatment that weakens the immune system.

Of the 11 cases reported statewide in 2014, both individuals in Sarasota County were middle-aged and had medically compromising conditions, according to the local Florida Department of Health. Both are believed to have contracted the infection when bacteria entered an open wound.

Two cases have also been reported this year in Charlotte County, and none so far in Manatee County. There were 41 Florida cases in 2013.

The Vibrio vulnificus bacteria — increasingly but not quite accurately referred to as “flesh-eating” — occur naturally in coastal waters, perhaps more abundantly in the summer months. Symptoms include stomach illness, fever or shock after eating raw seafood, especially oysters, or a wound infection after exposure to seawater or brackish water.

Michael Drennon, epidemiologist for Sarasota County, said that this year does not appear to be any worse or better than any other, in terms of presence of the bacteria.

“The risk would be equal to any year,” Drennon said. “V. vulnificus likes warm, salty water; that's where it lives. There's speculation that the bacteria grow better in the warmer water, but it is warm enough here in wintertime, and we see Vibrio cases throughout the year.”

Floridians and visitors without flesh wounds or underlying medical conditions should not be alarmed, he added.

“For people that have no open wounds, there's no reason why they shouldn't go in the water,” Drennon said.

Jay Grimes, a professor at the University of Southern Mississippi's Gulf Coast Research Laboratory who has studied Vibrio bacteria since 1980, agrees.

“The misunderstanding about this infection is that everyone's at risk,” he said. “You're only at risk if you have these compromising factors. Otherwise, you might get infected but you're going to get an abscess that will heal, and that's about it.”

Swallowing water while swimming is not a danger, Drennon and Grimes said. The gastrointestinal form of the infection can only be contracted by eating raw or undercooked fish.

V. vulnificus, a relative of the bacteria that cause cholera, requires salt to survive.

Most U.S. cases occur in the Gulf Coast states, according to the Centers for Disease Control and Prevention.

Severe infections have a 50 percent chance of becoming fatal. Although anyone can be exposed to the bacteria through an open wound, exposure through a puncture wound is more apt to lead to an infection. Swelling, pain or redness at the site can signal the need for immediate medical attention.

Drennon said the Southwest Florida health care community is aware of the Vibrio threat and “will test appropriately” for it. Antibiotic treatment, if administered early, greatly increases the chances of survival. Those who recover from the infection should not expect any long-term consequences.

While the department tests Gulf waters in beach areas for enteric bacteria — from human or animal waste — there is no testing for V. vulnificus.

Even legally harvested oysters can be contaminated, because the bacterium is naturally present in marine environments. The appearance, taste, or odor of oysters are no indication that they are safe to eat, according to the CDC.

More recent media reports about V. vulnificus are referring to them as “flesh-eating bacteria,” a term originally applied to streptococcus and staph infections — often acquired in hospitals — also known as Necrotizing Fasciitis.

“Seeing that as the headline is new to me,” Drennon said. “But I'm sure in certain situations that might occur.”

Grimes said lumping V. vulnificus into the “flesh-eating” category isn't completely off-base: severe skin wounds display the same destruction of tissues and can lead to the loss of an arm or leg. Plus, he said, it heightens awareness of the threat.

“I don't really like the term,” he said, “but people understand it and know it.”

Vulnificus is the only form of 12 Vibrio bacteria that can cause flesh-eating, Grimes said. They co-evolved with crabs and fish, and he has seen cases of fatalities in red snapper grown in fish farms at his university.

“These bacteria don't swim; they like to attach to things, like oyster shells and dock pilings,” he explained. “From there, they like to jump into humans.”

Besides cholera and vulnificus, the Vibrio family also includes V. parahaemolyticus, the more common infection from eating seafood or swimming with an exposed wound. This kind is rarely fatal, and its food-poisoning effects last only about three days.

Grimes and his colleagues recently published a paper that linked the presence of V. vulnificus and parahaemolyticus to water salinity levels. They tested Gulf waters before and after engineers took steps to reduce flooding in the Mississippi River near New Orleans.

“When they opened the Bonnet Carre Spillway gates, a tremendous amount of freshwater came into the Mississippi Sound,” Grimes said. “Interestingly, cholera thrived, and the vulnificus and parahaemolyticus disappeared.”

For those who like to fish in Gulf waters, Grimes advises them to prevent the ever-present risk of Vibrio skin infections by keeping hydrogen perioxide and Betadine in their tackle boxes.

“Hydrogen peroxide is not an antiseptic, but when you pour it on a wound, the bubbling has a cleansing effect,” he said. “Then if you put Betadine on it, chances are good you won't get an infection.”

EARLIER: Two Sarasota County cases this month of a serious “flesh-eating bacteria” — one of them fatal — prompted local health officials on Tuesday to issue a warning against eating raw oysters and exposing open wounds to coastal and inland waters.

This urgent advisory applies particularly to residents and visitors with chronic diseases that make them more vulnerable to the dangerous infection. These include liver disease — including Hepatitis C and cirrhosis — hemochromatosis (iron overload), diabetes, cancer, stomach disorders or any illness or treatment that weakens the immune system.

Of the 11 cases reported statewide in 2014, both individuals in Sarasota County were middle-aged and had medically compromising conditions, according to the local Florida Department of Health. Both are believed to have contracted the infection when bacteria entered an open wound.

Two cases have also been reported this year in Charlotte county, and none so far in Manatee County. There were 41 Florida cases in 2013.

The Vibrio vulnificus bacteria occur naturally in coastal waters, especially in the summer months. Symptoms include stomach illness, fever or shock after eating raw seafood — especially oysters — or a wound infection after exposure to seawater or brackish water.

Severe cases have a 50 percent of becoming fatal. Although anyone can be exposed to the bacteria through an open wound, exposure through a puncture wound is more apt to lead to an infection.

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